A blog about search, search skills, teaching search, learning how to search, learning how to use Google effectively, learning how to do research. It also covers a good deal of sensemaking and information foraging.

Wednesday, March 9, 2016

In 1968 Dionne Warwick famously sang... ... "Do You Know the Way to San José?" Which asked that question, wondering if she could go back there to "find some peace of mind..." because she was "born and raised in San José" and there's "lots of space there..." Things have changed a bit since 1968. But the quest to find your way never ends. A while back Regular Reader Jon ("The Unknown") wrote in with a great question. "If I start from my house and fly NE, keeping my plane flying in a straight line, what country do I next enter?" It's a great question, but "Do you know where I land if I fly northeast?" doesn't quite scan in a song form. (Sorry, Jon. Great question; terrible lyric.) As it turns out, Jon tU lives very near to Vancouver, BC. So I've modified his question just a bit to make it just a tad simpler. (And for these Challenges, you can safely ignore all weather issues... it's a perfect flying day all over the planet!)Here's the start of Jon's hypothetical flight path:

1. If Jon flies from the Vancouver, BC, airport on a NE heading, and flies in a straight-line, swerving neither to the left or the right, what's the next country he'll fly over? (And for extra credit, what's the name of airport he should land at?) 2. If Jon is flying an Airbus A340-200, about how long will the flight take? (Again, ignore weather, headwinds, tailwinds, etc.) 3. What distance is it from Vancouver to this mysterious destination's biggest airport (that is, where can he safely land his Airbus A340-200 in that country)? 4. Can he make it there without refueling? If you're up to the Challenge, be sure to let us know HOW you found the answer. As Jon writes, "This is a matter of thinking about how search it out..." And he's right--using what you've learned here, you should be able to do this fairly easily. Enjoy. And Search On!

20 comments:

1. Jon will fly first over Greenland. He should land at the Kangerlussuaq Airport, which is Greenland's largest. I used Google maps to see what country a plane would fly over. I then googled 'airports in Greenland' and found them on Google maps.2. The economical cruising speed of this plane is 880 km per hour; the flight should take just under 5 hours. I found information about the Airbus A340-200 on the Airbus website and on a site called airliners.net.3. The distance between Vancouver and Kangerlussuaq Airport is 4358 km. Googled this. Distance between Vancouver and Kangerlussuaq Airport.4. The 'optimal range' for the Airbus A340-200 is 6700 nautical miles. 4358 km equals about 2354 nautical miles, so no refueling will be necessary. Found this information on the airbus site.

1) The next country is Morocco. First, I knew there was a map projection that made great circles straight lines so I first did a search [map projection great circles straight lines]. This returned the Gonomonic projection and I skimmed the Wikipedia article to confirm.

The wikipedia article had a nice, large gnomonic map centered on the north pole which I downloaded and used to draw a line NE from Vancouver on. This showed me that I would be somewhere near Spain/Portugal or NW Africa. However, couldn't get the angle accurate enough to be sure.

So I switched over to Google Maps and used the "measure distance" function which will draw a great circle on the map. On Maps I drew a line out to Portugal and then checked a close up on the region provided and realized that circle was flying over the western end of the lake by Kamloops and not the more eastern end. I shifted the end point of my great circle until it passed over the same part of the lake as in the image. That circle has the flight just missing the tip of Portugal and making Morocco the first country after leaving Canada.

Using the measure distance feature also told me it would be 5,500 mi to the coast which will be useful for the later questions.

2) Searching for [Airbus A340-200 specifications] gives a page on Airbus's website with the information on the aircraft's range and its max speed. The max speed is given as Mach 0.86 or 568 mph. The Wikipedia article on the aircraft (further down on the SERP) gives a cruising speed of Mach 0.82 or 537 mph. So a 5,500 mile trip will take 10h 15m at the cruising speed or 9h 40m at the max speed.

3) The distance to Morocco's biggest airport, located in Casablanca, is almost exactly the 5,500 miles used above. This was found by moving my measure distance line to the airport on the map.

4) The range of the Airbus A340-200 is 6,700 miles so it can easily make it in one trip without refueling.

1. If Jon flies from the Vancouver, BC, airport on a NE heading, and flies in a straight-line, swerving neither to the left or the right, what's the next country he'll fly over? (And for extra credit, what's the name of airport he should land at?)

Ramón - nice find with the Time&Date/Distance Calculator site - like the headings/directions indicators - the key seems to be Dan's hypothetical flight path for jon… following that line seems to eliminate Greenland even though it is on a NE heading also… btw, my in-flight snack pak was missing the toasted pepitas bagbetter than egusi, imo…, but the dried apricots were tasty.Vancouver and Casablanca~10 hrs in a tube is a long time… actual is much longerserp

[flight time vancouver to casablanca] is great and very useful to find information and your wolfram question results are very interesting. I think they show less time because only account distance and speed and the results in serp adds more info, right?

Why is Greenland eliminated? I understand why Casablanca is a good choice but "NE heading, and flies in a straight-line, swerving neither to the left or the right" for me is going up and right. That is why I don't understand Morocco. You need to go down to get there. Iceland also good answer but you need to fly over Greenland first.

Ramón - hope this makes sense… I'm fuzzy on the math, but hopefully the maps will illustrate the thought…one flight path "straight line" leads to Morocco, the other "straight line" leads to Greenland… the passage near Kamloops sets the trajectory… (as pointed out by Tom Stephens/Teri Obar in his answer)comparison - Morocco/Greenland flight pathsfwiw, it does come close to Portugal…"The minor arc of a great circle between two points is the shortest surface-path between them. In this sense the minor arc is analogous to “straight lines” in Euclidean geometry."from: wiki - great circlegoogle flightsgreat circlemapperbtw, Google flights shows a similar map too… along with prices and much other info; e.g., carriers, flight times, # of stops/layovers, links to destination info, etc. …gFlights

The easiest way to solve this was to generate a great circle (azimuthal) map based on Vancouver Airport; I used the map generator at http://ns6t.net/azimuth/azimuth.html (getting the coordinates for the airport from Wikipedia). Generate the map and look at what you encounter on the 45-degree line - the first country you fly over is Greenland.

like Tom Stephens's Casablanca answer - clever use of the measure tool in Maps - didn't ever think to use it on great distances that would incorporate the great circle…the mapDan, will your brother contribute "flight truth"? nice change of pace question this week… thanks to you & jon tUfwiw - I was leaning toward Keflavík International Airport (Icelandic: Keflavíkurflugvöllur) (IATA: KEF, ICAO: BIKF) initially… several flaws with that line of thought…

(49°11'40"N by 123°11'2"W)YVR (not YRV - close, but no ḥuqqah)>(33°22'1"N by 7°35'22"W)CMNpt2ptinfo…for geographic harmony's sake, I thought jonTU would opt for the 787… more 'green?', but more greenies… range would not be an issue…Dreamlinera cost comparison642' vertical differential (14 v 656 - what's the elevation of jon's drive/runway?) … higher near Berrechid

Why this plane? Its big enough for grandkids and a few friends. But its small enough so that my missus and I can handle it all ourselves. The price was right. Started flying in this particular azimuth because I can take=off down the road beside my house, which, due some survey magic back in the day, laid it out precisely NE/SW. Naturally we wanted to see what was at the end of the rainbow, so off we went.

We have some secret beaches we like in Portugal and St Lucia and other spots. There are weekend bridge parties for us in Paris and Atlanta too.

Does this pass the 'sniff' test?

jon tU who is impressed with the determination you all show to solve this thing. And Dan for his obfuscation.

What is a straight line? I guess Greenland is so big it doesn't really matter in this case, but wouldn't the answer vary based on the projection of the map you are using? That is assuming you had a different starting point.